System and Method for Manufacturing a Swallowable Sensor Device

ABSTRACT

Methods and systems for manufacturing a swallowable sensor device are disclosed. Such a method includes mechanically coupling a plurality of internal components, wherein the plurality of internal components includes a printed circuit board having a plurality of projections extending radially outward. A cavity is filled with a potting material, and the mechanically coupled components are inserted into the cavity. The cavity may be pre-filled with the potting material, or may be filled after the mechanically coupled components have been inserted therein. A distal end of each projection abuts against a wall of the cavity thereby preventing the potting material from covering each distal end. The cavity is sealed with a cap causing the potting material to harden within the sealed cavity to form a housing of the swallowable sensor device, wherein the distal end of each projection is exposed to an external environment of the swallowable sensor device.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to medical diagnostics, and in particular,to swallowable medical diagnostic devices.

2. Background Art

The population of the United States is aging. The first wave of the 78million “Baby Boomers” is beginning to turn 60 years old. There has beenan explosion in diabetes cases, estimated at 194 million cases worldwidetoday, and predicted to reach 350 million cases by year 2025. Obesitycurrently affects two thirds of the U.S. population. There is a risingincidence of cardiac problems for women (the number one cause of deathfor women). Hepatitis C will soon reach epidemic levels, infectingnearly 5 million people, more than the number of people infected withAIDS in the U.S. Thus, simple and easy diagnostic and treatmenttechniques are needed, especially because many of the diseases thatafflict the population are chronic, requiring repeat testing andtreatment over time.

Such diagnostic and treatment techniques may be realized by using aswallowable sensor device that is ingested by a patient. The swallowablesensor device could be used to sense a condition and/or deliver medicaltreatment as it travels through the patient's gastrointestinal tract.

However, conventional swallowable sensor devices have several drawbacks.One drawback of conventional swallowable sensor devices is that they arequite large. In fact, conventional swallowable sensor devices are solarge that a portion of the patient population cannot even swallow thesedevices. Even if a patient could swallow a conventional swallowablesensor device, its large size could cause it to become lodged in thepatient's gastrointestinal tract, which would require surgery to remove.

Another problem with conventional swallowable sensor devices is thatthey use a radio frequency (RF) signal platform to communicate withexternal entities. The extent to which RF signals cause harm to humantissue is not fully understood. The potential for harm only increases asthe source of the RF signals comes closer to human tissue. As a result,many patients are apprehensive about ingesting conventional swallowablesensor devices.

Given the foregoing, what is needed is an improved swallowable sensordevice, and a method for manufacturing such a swallowable sensor device.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

The accompanying drawings, which are incorporated herein and form partof the specification, illustrate the present invention and, togetherwith the description, further serve to explain the principles of theinvention and to enable a person skilled in the relevant art(s) to makeand use the invention.

FIG. 1 illustrates an example environment in which a swallowable sensordevice may operate in accordance with an embodiment of the presentinvention.

FIGS. 2A and 2B illustrate example embodiments of a swallowable sensor.

FIG. 3 illustrates an example method for manufacturing a swallowablesensor device in accordance with an embodiment of the present invention.

FIGS. 4, 5, 6, 6A, 6B, and 7 illustrate various manners in whichinternal components of a swallowable sensor device are mechanicallyand/or electrically coupled to each other in accordance with embodimentsof the present invention.

FIG. 8 illustrate example molds used for manufacturing a swallowablesensor device in accordance with an embodiment of the present invention.

FIGS. 9A and 9B respectively illustrate a cross-sectional view and sideview of internal components of a swallowable sensor device disposed in amold in accordance with an embodiment of the present invention.

FIG. 10 illustrates an example printed circuit board in accordance withan embodiment of the present invention.

FIG. 11 illustrates an example sensor in accordance with an embodimentof the present invention.

FIG. 12 illustrates a swallowable sensor including a plurality ofsensors in accordance with an embodiment of the present invention.

FIG. 13 illustrates an exemplary computer system useful for implementingan embodiment of the present invention.

FIGS. 14A-D illustrate a swallowable sensor according to anotherembodiment of the present invention.

FIGS. 15A-D depict several configurations of time released biologicalsensors according to embodiments of the present invention.

FIG. 16 depicts an example micro-pump according to an embodiment of thepresent invention.

FIGS. 17A-D illustrate an example packaging assembly according toembodiments of the present invention.

FIGS. 18A-B illustrate a machine that uses the example packagingassembly of FIGS. 17A-D.

FIGS. 19 and 20 illustrate a swallowable sensor device having a layeredstructure for efficient power transfer according to embodiments of thepresent invention.

The features and advantages of the present invention will become moreapparent from the detailed description set forth below when taken inconjunction with the drawings, in which like reference charactersidentify corresponding elements throughout. In the drawings, likereference numbers generally indicate identical, functionally similar,and/or structurally similar elements. The drawing in which an elementfirst appears is indicated by the leftmost digit(s) in the correspondingreference number.

DETAILED DESCRIPTION OF THE INVENTION I. Overview

Described herein are methods and systems for manufacturing a swallowablesensor device, and applications thereof. In the specification,references to “one embodiment,” “an embodiment,” “an exampleembodiment,” etc., indicate that the embodiment described may include aparticular feature, structure, or characteristic, but every embodimentmay not necessarily include the particular feature, structure, orcharacteristic. Moreover, such phrases are not necessarily referring tothe same embodiment. Further, when a particular feature, structure, orcharacteristic is described in connection with an embodiment, it issubmitted that it is within the knowledge of one skilled in the art toaffect such feature, structure, or characteristic in connection withother embodiments whether or not explicitly described.

A swallowable sensor device manufactured in accordance with anembodiment of the present invention is relatively small compared toconventional swallowable sensor devices. In addition, a swallowablesensor device manufactured in accordance with an embodiment of thepresent invention uses acoustic frequencies, rather than RF frequencies,to communicate with an external entity (such as a computer or hand-helddevice). As a result, the swallowable sensor device may be ingested by apatient for diagnostic or treatment purposes. To diagnose the patient,the swallowable sensor device may collect data and/or samples as ittravels through the gastrointestinal tract of the patient. To treat thepatient, the swallowable sensor device may deliver medication or othertypes of treatment at specific locations within the patient's body.Similarly, the swallowable sensor device may deliver material to augmenta particular sensor device or an external diagnostic procedure, such asa dye, marker, or radioactive isotope.

The diagnostic and treatment functionalities are performed bydiagnostic/treatment components of the swallowable sensor device. Thediagnostic/treatment components are exposed to the external environmentof the swallowable sensor device. For example, sensors of theswallowable sensor device are exposed to fluids and acids within thepatient's gastrointestinal tract in order to collect data regarding thepatient's internal body chemistry. Similarly, treatment deliverycomponents are exposed to the external environment of the swallowablesensor device in order to deliver certain types of treatment to thepatient.

Circuitry contained within the swallowable sensor device controls theimplementation of the diagnostic and/or treatment functionalities.Although the diagnostic/treatment components are coupled to thecircuitry, the circuitry and other internal components (such as a powersupply, a communication module, and other such components) are notexposed to the external environment. Exposing the circuitry and otherinternal components to the external environment would likely cause theswallowable sensor device to malfunction, and/or could also be harmfulto the patient.

To expose the diagnostic/treatment components, while protecting theinternal components, an embodiment of the present invention uses amolding technique to manufacture a swallowable sensor device. In thisembodiment, the internal components of the swallowable sensordevice—such as a printed circuit (PC) board, a battery, and atransducer—are mechanically and electrically coupled to each other. Theinternal components are inserted into a molding cavity. The cavity maybe pre-filled with a potting material or the potting material may beinjected into the cavity after the internal components have beeninserted therein. The cavity is then sealed, allowing the pottingmaterial to harden. The hardened potting material forms an exteriorhousing that protects the internal components of the swallowable sensordevice from the external environment.

In an embodiment, the potting material comprises a UV curable epoxy. Inthis embodiment, the chemical composition of the potting materialresults in an acoustically transmissive substance (transmissive at adesired acoustic frequency) with an impedance between that of atransducer and the human body. Furthermore, curing the UV epoxy in anoxygen rich environment results in a layering of the cure, which in turnresults in a layering of the impedance from the potting materialabutting the transducer and the external layer of the swallowable sensordevice. Ideally, the swallowable sensor device includes an infinitenumber of layers from the acoustic impedance of the transducer to theacoustic impedance of the human body, resulting in the highest possibleacoustic performance (i.e., the most energy transmitted outward from theacoustic source). Accordingly, embodiments of the present inventioninclude a relatively large number of layers of acoustic impedancebetween the transducer and the human body. The aforementioned layeredimpedance construction yields a highly efficient swallowable sensordevice in acoustic performance.

Importantly, the PC board includes a plurality of projections thatextend radially outward causing them to abut against the cavity wall.Because the projections abut against the cavity wall, the pottingmaterial is prevented from covering the distal ends of the projections.As a result, when the potting material hardens to form the exteriorhousing, the projections will be exposed to the then externalenvironment. However, the projections will be mechanically and/orelectrically coupled to the internal components of the swallowablesensor device.

Each projection may comprise an electrode or a hollow tubing. Theelectrodes are coupled to sensors that collect data corresponding to theinternal body chemistry of a patient. Because the housing does not coverthe electrodes, the sensors will be exposed to the external environmentof the swallowable sensor device, but electrically coupled to internalcomponents. Thus, the sensors can properly function to receive stimulifrom the external environment, which can then be communicated tointernal circuitry contained within the swallowable sensor device.

Additionally, each sensor may be covered with a digestible, protectivematerial.

As the swallowable sensor device travels through a human'sgastrointestinal tract, the protective material covering each sensor isdigested. By covering the sensors with different thicknesses ofprotective material, the sensors can be exposed to the externalenvironments at different times as the swallowable sensor device travelsthrough a human's gastrointestinal tract. Thus, the swallowable sensordevice can be configured for timed release of each sensor based on thethickness of the digestible, protective material covering each sensor.

Similar to each electrode, a first end of the hollow tubing is exposedto the external environment and a second end is coupled to a containerthat is sealed within the housing of the swallowable sensor device.Thus, the hollow tubing can properly function to deliver materials andtreatment to and/or collect samples from the external environment of theswallowable sensor device.

The methods and systems of the present invention for manufacturing aswallowable sensor device are described in greater detail below. Tobetter understand these methods and systems, however, it is firsthelpful to describe an example environment in which such a swallowablesensor device may be implemented and an example swallowable sensordevice.

II. An Example Environment

FIG. 1 shows an example environment 100 in which a swallowable sensordevice 104 may be used in accordance with an embodiment of the presentinvention. Environment 100 includes a human 102, a swallowable sensordevice 104, an external computing device 108, and optionally includes anetwork 170 and a remote entity 190. As illustrated in FIG. 1,swallowable sensor device 104 is disposed in human 102. Swallowablesensor device 104 is configured to sense one or more attributes orconditions of, and/or deliver medical treatment or materials to, human102 as swallowable sensor device 104 passes through human 102, asdescribed for example in U.S. Patent Application No. 60/842,360 toArneson et al., entitled “Swallowable Low Power Sensor Device and Systemfor Communication with Same” and filed Sep. 6, 2006, the entirety ofwhich is incorporated by reference herein.

While passing through human 102, swallowable sensor device 104 transmitsinformation in a communication signal 106 to be received outside human102. As shown in FIG. 1, external computing device 108 may receivecommunication signal 106. Computing device 108 may be used to displaythe information received in communication signal 106, to interact withthe information, to process the information, and/or to transmit theinformation (raw or processed) to another entity. Example systems andmethods for transmitting data from swallowable sensor device 104 toexternal computing device 108 are described, for example, in U.S.Provisional Patent Application No. 60/941,184 to Arneson et al.,entitled “System and Method for Acoustic Data Transmission Involving aSwallowable Low Power Sensor Device” and filed May 31, 2007; U.S. patentapplication Ser. No. 11/851,214 to Arneson et al., entitled “System andMethod for Acoustic Data Transmission Involving a Swallowable Low PowerSensor Device” and filed Sep. 6, 2007; U.S. patent application Ser. No.11/851,236 to Arneson et al., entitled “System and Method for AcousticData Transmission” and filed Sep. 6, 2007; and U.S. patent applicationSer. No. 11/896,946 to Arneson et al., entitled Methods and Systems forAcoustic Data Transmission and filed Sep. 6, 2007. The entirety of eachof the foregoing applications is incorporated by reference herein.

In an embodiment, computing device 108 can interact with swallowablesensor device 104 by transmitting a communication signal 110. Suchinteraction may be used to control functions of swallowable sensordevice 104 and/or to image at a desired resolution an internal portionof a patient, as described for example in U.S. Provisional PatentApplication No. 60/924,928 Arneson et al., entitled “Imaging andLocating Systems and Methods for a Swallowable Sensor Device” and filedJun. 5, 2007, and U.S. patent application Ser. No. 11/851,179 to Arnesonet al., entitled “Imaging and Locating Systems and Methods for aSwallowable Sensor Device” and filed Sep. 6, 2007. The entirety of eachof the foregoing applications is incorporated by reference herein.

In embodiments, human 102 may be provided with one or more swallowablesensor devices 104 that human 102 may swallow at designated times and/orperiodically to perform an analysis of one or more health-relatedconditions of human 102.

Computing device 108 may be configured to communicate with remote entity190 using wired and/or wireless links, in a direct fashion or throughnetwork 170. For example, computing device 108 transmits a communicationsignal 160 to network 170, which transmits a communication signal 180 toremote entity 190. Network 170 may be any type of network or combinationof networks, such as a telephone network (e.g., a land line and/orcellular network), a personal area network (PAN), a local area network(LAN), and/or a wide area network (WAN) such as the Internet.

Remote entity 190 may be one or more of a variety of entities, includinga human and/or computer-based entity. For example, remote entity 190 mayinclude a doctor who receives information collected by swallowablesensor device 104 (and optionally processed by computer device 108) incommunication signal 180.

Remote entity 190 may send a return communication to computing device108 via network 170. For example, a return communication signal 182 istransmitted by remote entity 190 to network 170, which transmits areturn communication signal 162 to computing device 108. In this manner,remote entity 190 (e.g., doctor and/or computer system) can providefeedback to computing device 108 in communication signal 182 regardingthe analysis of human 102 performed by swallowable sensor device 104.Return communication signal 182 may include any type of data/informationformat for providing the feedback, including an email, a text message, atext file, a document formatted for commercially available wordprocessing software, a proprietary document/data format, auditoryalarms, alerts and messages, etc. In addition, computing device 108 maysend instructions to swallowable sensor device 104 in communicationsignal 110 based on the feedback provided from remote entity 190 vianetwork 170.

Swallowable sensor device 104 may optionally communicate with computingdevice 108 via an intermediate sensor link module 112. Sensor linkmodule 112 may receive communication signal 106 from swallowable sensordevice 104. Sensor link module 112 transmits a communication signal (notshown) to computing device 108 on a wired or wireless connection, toprovide the information sensed by swallowable sensor device 104 tocomputing device 108. For example, sensor link module 112 may be usedwhen swallowable sensor device 104 communicates using an acousticcommunications signal having a power level too low to reliably bereceived by computing device 108.

In another embodiment, sensor link module 112 may provide acommunication interface between swallowable sensor device 104 andnetwork 170, such that a separate computing device 108 is not required.In such an embodiment, sensor link module 112 may perform some or allfunctions of computing device 108 described above, and thus sensor linkmodule 112 may be referred to as a computing device. For example sensorlink module 112 may receive communication signal 106 from and transmitcommunication signal 110 to swallowable sensor device 104.

Multiple sensor link modules 112 may provide a capability of accuratelylocating swallowable sensor device 104 as it travels through human 102.Example locating systems and methods are described in the aforementionedU.S. Provisional Patent Application No. 60/924,928 to Arneson et al.,entitled “Imaging and Locating Systems and Methods for a SwallowableSensor Device” and filed Jun. 5, 2007, and U.S. patent application Ser.No. 11/851,179 to Arneson et al., entitled “Imaging and Locating Systemsand Methods for a Swallowable Sensor Device” and filed Sep. 6, 2007. Theentirety of each of the foregoing applications is incorporated byreference herein.

As shown in FIG. 1, sensor link module 112 is coupled to human 102. Inan embodiment, multiple sensor link modules 112 may be attached to human102 at various locations in order to receive the interior acousticsignal from different angles. Sensor link module 112 may be, forexample, directly attached to the skin of human 102, such as by anadhesive strap, an integrated flexible fabric assembly such as a belt orgirdle. Sensor link module 112 may be attached to human 102 in one ormore locations, including the head, neck, chest, back, abdomen, arm,leg, etc. With regard to receiving communication signal 106 fromswallowable sensor device 104 passing through the gastrointestinaltract, sensor link module 112 may be attached to the neck, chest, back,and/or abdomen for a short signal path.

III. An Example Swallowable Sensor Device

FIGS. 2A and 2B illustrate swallowable sensor device 104 according toembodiments of the present invention. FIG. 2A illustrates structuralcomponents of swallowable sensor device 104. FIG. 2B is a block diagramillustrating functional components of swallowable sensor device 104.Each of these figures is described in more detail below.

Referring to FIG. 2A, swallowable sensor device 104 includes a housing208 that holds a plurality of internal components, including printedcircuit (PC) boards 220 a-c, a transducer (transmitter) 240, and abattery 260. In the embodiment illustrated in FIG. 2A, the plurality ofinternal components are mechanically and electrically coupled to eachother by a post 230. In other embodiments, the plurality of internalcomponents are mechanically and electrically coupled using other means,as illustrated for example in FIGS. 4-7.

Housing 208 may be the size of a vitamin or other type of pill that isswallowable by humans. For example, housing 208 may be approximately 1mm to 10 mm in diameter and approximately 4 mm to 25 mm in length, andpreferably approximately 5 mm in diameter and approximately 14 mm inlength. Housing 208 may be any suitable shape, including oval,elliptical, capsule shaped, or spherical. The small size of housing 208allows swallowable sensor device 104 to be easily ingested by an averagehuman 102. The small size overcomes difficulties present withconventional swallowable sensor devices, which are often so large thatonly a small percentage of the population can actually swallow themsafely. Further, the small size of housing 208 allows swallowable sensordevice 104 to pass completely through the digestive system of a human102 without becoming trapped due to size incompatibilities or blockage(growths) along the way.

Housing 208 may be made from a variety of non-digestible or slow rate ofdigestion materials. Such materials may include, but are not limited to,the following materials: a plastic material (such as a resin, aresinoid, a polymer or polymer matrix, a cellulose derivative); a caseinmaterial; a protein; a metal (including a combination of metals/alloy);a glass material; a ceramic; a composite material; an enteric coating;and/or other material/combination of materials. In an embodiment,housing 208 may be comprised of a material that aids in the sensing ofbiological, chemical, or other attributes of body material that touchesor comes in close proximity to the housing 208, such as could be calledan integrated housing and sensor material. Furthermore, in anembodiment, housing 208 comprises primarily a non-digestible materialwith orifices or indentations which are filled with a layer ofdigestible material of variable thickness covering a sensor materialthat is in turn deposited on top of an electrically conductive pathwayto internal components.

Swallowable sensor device 104 also includes treatment/diagnosticcomponents 202, such as a treatment delivery component 202 a, a samplereceiver component 202 b, and a sensor 202 c. Treatment/diagnosticcomponents 202 are coupled to PC boards 220 a-c, but are not containedwithin materials comprising housing 208. In other words,treatment/diagnostic components 202 are exposed to the externalenvironment of swallowable sensor device 104 in order to delivertreatment and/or collect data as swallowable sensor device travelsthrough the gastrointestinal tract of human 102. Treatment deliverycomponent 202 a is configured to deliver treatment (such as medication,radiation therapy, or another form of treatment or therapy) to human102. Sample receiver component 202 b is configured to receive one ormore samples (such as digestive fluid, stomach acid, tissue, or someother sample) from human 102. Sensor 202 c is used to sense (e.g.,measure, detect, etc.) a received stimulus 210. Swallowable sensordevice 104 can include any number of sensors 202 c, each of which mayall sense the same condition or may sense a different condition thananother sensor 202 c. In an embodiment, a molding technique is used toseal the internal components within housing 208, while exposingtreatment/sensor components to the external environment—as described inmore detail below.

In an embodiment, the treatment/sensor components may be covered by adigestible, protective material. By applying different thicknesses ofprotective material, the treatment/sensor components can be released atdifferent times corresponding to the amount of time it takes to digestthe protective material, as described in more detail below.

A first end 232 and a second end 234 of post 230 are also exposed to theexternal environment of swallowable sensor device 104. A voltage and/orsignal may be applied across first end 232 and second end 234, afterswallowable sensor device 104 is fabricated, to test whether swallowablesensor device 104 is functioning properly, as described in more detailbelow.

FIG. 2B is a block diagram illustrating functional components ofswallowable sensor device 104 in accordance with an embodiment of thepresent invention. Although FIG. 2B illustrates swallowable sensordevice 104 as having only three treatment/diagnostic components 202, oneof skill in the art will recognize that treatment/diagnostic components202 may be included, but are not limited to, a plurality of treatmentdeliver components 202 a, a plurality of sample receiver components 202b, and/or a plurality of sensors 202 c, as illustrated in FIG. 2A.Treatment/diagnostic components 202 send output to, or receive inputfrom, communications module 204 via an electrical coupling 212.Communications module 204 may comprise PC boards 220 and transducer 240of FIG. 2A. Electrical coupling 212 may comprise an electrical tracedisposed one or more PC boards 220, an electrical trace or tracesdisposed on a post 230 in electrical contact with electrical traces onPC board 220, a wireless communication link, or some other type ofelectrical coupling.

Communications module 204 receives the output from treatment/diagnosticcomponents 202 and generates communication signal 106 to include databased on the output. Communication signal 106 is transmitted fromswallowable sensor device 104. Communications module 204 may alsoreceive communication signal 110 transmitted from external computingdevice 108.

In an embodiment, communication signal 106 comprises an acoustic signal.In this embodiment, communications module 204 includes one or moretransducers (such as transducer 240) that are configured to convertelectrical energy to mechanical energy, and vice versa. For example, theone or more transducers convert the electrical energy received fromtreatment/diagnostic components 202 into the mechanical energy ofacoustic communication signal 106, and convert the mechanical energy ofacoustic communication signal 110 into electrical energy sent tocommunications module 204, control logic 214, or treatment/diagnosticcomponents 202. Example methods and systems for transmitting data fromswallowable sensor device 104 are described, for example, in theaforementioned U.S. Provisional Patent Application No. 60/941,184 toArneson et al., entitled “System and Method for Acoustic DataTransmission Involving a Swallowable Low Power Sensor Device” and filedMay 31, 2007; U.S. patent application Ser. No. 11/851,214 to Arneson etal., entitled “System and Method for Acoustic Data TransmissionInvolving a Swallowable Low Power Sensor Device” and filed Sep. 6, 2007;U.S. patent application Ser. No. 11/851,236 to Arneson et al., entitled“System and Method for Acoustic Data Transmission” and filed Sep. 6,2007; and U.S. patent application Ser. No. 11/896,946 to Arneson et al.,entitled Methods and Systems for Acoustic Data Transmission and filedSep. 6, 2007. The entirety of each of the foregoing applications isincorporated by reference herein.

Swallowable sensor device 104 also includes control logic 214, which maybe used to gate or control swallowable sensor device 104. Control logic214 may be included on one or more PC boards 220. Control logic 214 mayoperate in a sub-threshold voltage (Vt) manner (e.g., to save power), ormay operate in normal bias modes. In an embodiment, swallowable sensordevice 104 is an autonomous device with one way communication(transmission capability), so that control logic 214 may be extremelysimple, and thus would not consume much power even when operating innormal bias modes. In another embodiment, swallowable sensor device 104may communicate in both directions—i.e., it may be configured totransmit information to and receive instructions from computing device108 and/or sensor link module 112. Control logic 214 may thus haveadditional complexity in order to, for example, decode and implementreceived instructions.

Swallowable sensor device 104 also includes power source 206. Powersource 206 provides power (e.g., via electrical energy) to operate thecomponents of swallowable sensor device 104 that require power, such ascommunications module 204 and/or sensor 202. Power source 206 mayinclude, for example and without limitation, battery 260 of FIG. 2A, aliquid or gel surrounding communications module 204, an energyharvesting module, or some other power source.

In an embodiment, swallowable sensor device 104 is configured for lowpower operation, including extreme low power (XLP) operation. To achieveXLP operation, swallowable sensor device 104 can use one or both of avery small battery and energy harvesting to operate swallowable sensordevice 104. In an embodiment, circuits of swallowable sensor device 104are implemented on one or more integrated circuits (ICs), in atechnology such as CMOS, or other technology. The IC(s) and any otherinternal components of swallowable sensor device 104 are mounted to oneor more PC boards 220 of FIG. 2A. Thus, in embodiments, power source 206is configured for low power output, including supplying power in themilliwatt and microwatt ranges. Such low power requirements enable thesize of power source 206 to be minimal.

In a CMOS embodiment, MOSFET circuits may be configured to operate in adeep sub-threshold voltage (sub-Vt) mode, which lowers their switchingtime to acoustic switching frequencies, and lowers their powerconsumption by orders of magnitude. In such a mode the MOSFET devicesoperate as analog devices. Such operation was demonstrated in themid-1980's by Carver Meade with regard to eye and ear chips. Such a modeof operation eliminates the need for digitizing the sensor data, whichcan be very power intensive, and which further reduces the powerconsumption by a large factor.

After being swallowed by human 102, swallowable sensor device 104eventually passes from human 102, such as when human 102 has a bowelmovement to excrete waste. In an embodiment, swallowable sensor device104 is disposable.

It may be useful to have positive confirmation if and when sensor device104 has been excreted. In some humans 102, sensor device 104 may notpass through the digestive tract within an average life time of sensordevice 104. In an embodiment, a power source 206 (FIG. 2B) may be oflimited supply. When this power source is below a pre-determined level,control logic may cease all activities except for an occasional shortcommunications signal with proportionally large amounts of time nottransmitting nor processing. The communications signal is intended to beas short as possible to achieve lowest power consumption, but longenough to determine location. An external computing device 108 may thenbe able to determine a location and path of a last transmission todetermine the likelihood of an excretion. Optionally, a sensor linkmodule 112 is located in, on, or around the bowl of a toilet. Thisconfiguration signals excretion of a sensor device, and is an embodimentfor recovering swallowable sensor device 104 when having an acoustictransmission. Since a toilet bowl is filled with water, the acousticsignals 106 will transmit across the medium.

In another embodiment, swallowable sensor device 104 may be recovered(and recycled) for reuse. Depending upon the ability or control of thepatient, swallowable sensor device 104 may alternatively be insertedinto a lower gastrointestinal tract of human 102 as a suppositorydevice. In a further embodiment, sensor device 104 may also be placedwithin a female reproductive tract. In this further embodiment, sensordevice 104 is configured to sense body temperature, hormonal levels,cancer markers, and a variety of STDs. This embodiment is a potentialaid to conception and/or reproductive disease and cancer diagnoses.

Depending on the configuration of sensor 202, while passing throughhuman 102, swallowable sensor device 104 can sense conditions and/orfeatures of any part of the gastrointestinal tract or contents thereof,and any of the materials/fluids contained within and/or secreted by theorgans in the gastrointestinal tract or organs indirectly associatedwith the gastrointestinal tract. Swallowable sensor device 104 candeliver treatment to patient 102. Swallowable sensor device 104 can alsoreceive conditions or signals from even more remote body organs such asacoustic pickup of heartbeat and/or breathing and more indirectconditions such as temperature. In an embodiment, an imager device iscontained within swallowable sensor device 104 to allow visualobservation of the gastrointestinal tract of human 102.

Having presented a description of an example environment and swallowablesensor device, a method for manufacturing such a swallowable sensordevice is now described.

IV. Method For Manufacturing A Swallowable Sensor Device

A. Overview

FIG. 3 depicts a block diagram 300 illustrating an overview of anexample method for manufacturing a swallowable sensor device inaccordance with an embodiment of the present invention. Block diagram300 begins at a step 310 in which internal components of a swallowablesensor device are mechanically coupled. The internal components mayinclude, for example, PC boards 220, transducer 240, and battery 260 ofFIG. 2A. Other example internal components are described below. Asdescribed in more detail below (see FIGS. 4-7), the internal componentsmay be mechanically and/or electrically coupled together using a varietyof techniques—including using a central post, using outer posts,stacking the internal components, and/or a combination of thesetechniques.

In a step 320, a cavity is filled with a potting material, and in a step330, the mechanically coupled components are inserted in the cavity. Inan embodiment, step 320 occurs before step 330. In another embodiment,step 320 occurs after step 330. In other words, the cavity may bepre-filled with the potting material. Alternatively, the mechanicallycoupled components can be inserted into the cavity, and then the pottingmaterial can be injected therein. The potting material may include, butis not limited to, the following materials: a plastic material (such asa resin, a resinoid, a polymer, a cellulose derivative); a caseinmaterial; a protein; a glass material; a ceramic; a composite material;and/or other materials or combinations of materials.

In a step 340, the cavity is sealed with a cap. The cap contains thepotting material, forming the entire outside shape. The cavity may bepassive to UV, allowing UV curing potting materials to harden quickly.The cavity may also simply contain the potting material while it hardenswithout external influence. The internal components include a PC boardhaving a plurality of projections. As set forth above and described inmore detail below, the projections abut against a wall of the cavity,thereby preventing the potting material from covering a distal end ofeach projection. As a result, the distal ends are exposed to an externalenvironment of the swallowable sensor device upon the completion of thehardening of the potting materials.

B. Example Mechanical and Electrical Couplings

The mechanical and electrical coupling of the internal components is nowdescribed with reference to FIGS. 4-7. FIG. 4 illustrates an examplemanner for mechanically and electrically coupling the internalcomponents, such as PC board 220, using central post 230. In theembodiment illustrated in FIG. 4, PC board 220 is annularly-shaped andincludes a plurality of projections 422 a-i that extend radiallyoutward. As described herein, projection 422 may comprises an electrodeand/or a hollow tubing. Examples of electrode 422 include a wire(straight or bent), a flat metal bushing, a plated PC board surface, oreven a non-conductive covering to an electrical connection that can beeasily remove after the hardening of the potting material. Similarly,examples of hollow tubings 422 include a glass tube, a plastic tube, ametal tube, a tube manufactured from electrical-mechanical materialssuch as with a transducer 240 (but in a different shape), a rod ofmaterial that is removed after the potting materials harden, or thelike. These examples illustrate a few functions, and do not limit thescope of this invention by any exclusion. PC board 220 also includes aninner opening 438 having a plurality of knobs 424 that extend radiallyinward. Knobs 424 may each independently be mechanical and/or electricalin function.

Post 230 includes a plurality of grooves 432 encircling its exterior.Post 230 may also include traces 434 that are disposed on the exterior.The interior of post 230 includes an insulator layer 440 and a centralconductor 232. In one embodiment, central insulator layer 440 maycomprise a transducer that is configured to convert electrical energy tomechanical energy. Additionally or alternatively, an annularly-shapedtransducer may be coupled to post 230 by inserting post 230 into theinner opening of the annularly-shaped transducer 240, as illustrated forexample in FIG. 2A.

PC board 220 is mechanically coupled to post 230 by inserting post 230in opening 438. In an embodiment, post 230 and opening 438 are keyedsuch as not to be able to assemble in an incorrect configuration. Aspost 230 is inserted into opening 438 of PC board 220, inner knobs 424are urged into one of the grooves 432 providing a mechanical couplingand mechanical spacing as appropriate. In another embodiment, grooves432 are not required as mechanical spacing can be attained from spacingmaterials deposited onto PC board 220, transducer 240 and the like.Additionally, traces 434 come into electrical contact with inner knobs424 providing an electrical coupling between PC board 220 and post 230.Other internal components, such as a battery and transducer, aremechanically and electrically coupled to post 230 in a similar manner.

FIG. 5 illustrates another example manner for mechanically andelectrically coupling internal components in accordance with anembodiment of the present invention. The internal components illustratedin FIG. 5 include a battery 560, a first PC board 520, and a second PCboard 510. Central post 230 provides mechanical coupling along a commoncentral axis of first PC board 510, second PC board 520, and battery560. Electrical coupling between first PC board 510, second PC board520, and battery 560 is provided by outer posts 540.

FIG. 6 illustrates a further example manner for mechanically andelectrically coupling internal components of swallowable sensor device104 in accordance with an embodiment of the present invention. FIG. 6illustrates a stack 600 of components including PC boards, transducers,batteries, and sensors. Each PC board includes a plurality of spacers604. Spacers 604 provide mechanical and/or electrical coupling betweenthe PC boards in stack 600.

FIG. 6A illustrates a further refinement of FIG. 6. FIG. 6A illustratesa series of conductive paths 604, with a keyed or absent location 612 toassure correct alignment during assembly of a stack of components 600.An example of a keyed location 612 is a larger conductor, for example aconductor for ground. An example of an absent location is a missing holein the position of 612 assuring no conductor penetrates that location.Furthermore, spacers 608 provide mechanical alignment from board toboard, assuring parallel placement, proper electrical isolation, andoptionally sonic or ultrasonic signal isolation between boards in stack600. In this embodiment, spacers 608 do not need extremely accurateplacement, unlike conductors which typically require accurate alignmentto be properly inserted into a hole.

The assembly of stack 600 illustrated in FIG. 6A may include thefollowing steps: (i) prepare each board with affixing spacers 608; (ii)select a large conductor of length as long or longer than stack 600 infinality; (iii) place boards onto the large conductor one at a time,aligning the large conductor with keyed hole 612; (iv) insert currentassembly into a tapered tube or another fixture having an internaldiameter equal to the diameter of boards 600; and (v) insert conductors604 through the entire assembly 600 while aligned by previous step.

FIG. 6B illustrates an additional refinement of FIG. 6. FIG. 6Billustrates multiple keyed conductors 612, three to four in anembodiment. Conductive paths 604 are selected from materials to allowcompression in a first direction (such as a vertical or heightdirection) which is perpendicular to the surface of each PC board instack 600. Examples of conductive paths 604 include bent wire, springmetal bridging, soft metal deposits, or the like. Selection of othermaterials are possible by persons skilled in the art, and do not departfrom the spirit and scope of this invention. Spacers 608 (notspecifically illustrated in FIG. 6B) may be utilized to stop acompression of conductive paths 604 at a certain distance or compressionpressure, and are optional depending upon the assembly processrequirements. Furthermore, conductive paths 604 mate and electricallyconduct to areas on the reverse side of boards 600. Any of boards 600may electrically conduct pathway 604 directly to the opposite side, tapinto and utilize signals on pathway 604 in addition to conducting to theopposite side, may process and/or re-route signals to other pathways onthe opposite side, and also may not electrically conduct signals to theopposite side at all.

The assembly of stack 600 illustrated in FIG. 6B may include thefollowing steps: (i) start with a first board 600 or another fixturethat holds keyed conductors 612; (ii) place each and all of boards 600onto keyed conductors 612 assembly in a repetitive process until allboards are within the assembly area; (iii) compress boards 600 with apre-determined pressure or final distance of compression; (iv) securecompression by connecting first and last of boards 600 to keyedconductors 612, such as with solder or welding; and (v) remove assembly600 and trim keyed conductors 612 to flush surface.

FIG. 7 illustrates mechanically and electrically coupled internalcomponents 700 in accordance with an embodiment of the presentinvention. Internal components 700 include a first stack of PC boards710, a second stack of PC boards 720, batteries 740, a first transducer716, a second transducer 750, and a third stack of PC boards 760. The PCboards in first, second, and third stacks 710, 720, and 760 areseparated from each other by spacers. First stack of PC boards 710 ismechanically and electrically coupled to first transducer 716 by outerposts 714. First transducer 716 is coupled to second stack of PC boards720 via outer posts 722. The second stack of PC boards 720 ismechanically and electrically coupled to battery 740 by a thirdplurality of outer posts 726. Battery 740 is coupled to secondtransducer 750 via outer posts 770 and second transducer 750 is coupledto third stack of PC boards 760 via outer posts 780. First stack of PCboards 710 includes a first external conductor 732 and the third set ofPC boards 760 includes a second external conductor 734. Components 700are constructed such that external conductors 732 and 734 are notcovered with potting material during construction of sensor device 104.Electrical signals and power can be sent in or out of these exposedconductors conveniently located at opposing ends of sensor device 104after final assembly, testing, and potentially lifetime use.

C. An Example Molding Technique

Given the stack of mechanically and electrically coupled internalcomponents (as illustrated in FIGS. 4-7), the internal components may bemanufactured into a swallowable sensor device 104 using an injectionmolding technique as illustrated for example in FIG. 8. FIG. 8 includesinjection moldings 810 that includes a plurality of cavities, such ascavity 812, as shown in FIG. 8. The cavities may have a substantially ortotally circular cross-section either uniform in diameter throughout thelength of cavity 812, or tapered from one end to the other of cavity812. The base of each cavity may be substantially concave in order tomanufacture an exterior housing that is capsule-shaped.

Moldings 810 and cavities 812 may contain small indentations for sensors(not shown in FIG. 8). These small indentations provide a receiving areain the hardened potting material. Use of these cavities is explained inmore detail in section E below. Additionally, small indentations and/orgrooves in cavities 812 may provide alignment for inserting components832 into cavities 812.

A plurality of stacks of mechanically coupled internal components 830 isinserted into molds 810. For example, a mechanically coupled stack ofinternal components 832 is inserted in cavity 812. In an embodiment,each cavity of molding 810 is pre-filled with potting material 820before inserting the internal components 830 therein. In anotherembodiment (not shown), the internal components 830 are inserted inmolds 810, and then potting material 820 is injected therein.

In either embodiment, molds 810 are sealed with caps 840, after theinternal components 830 and potting material 820 have been inserted inmolds 810. For example, cap 842 seals cavity 812 after stack 832 andpotting material 820 is inserted in cavity 812. As a result, pottingmaterial 820 hardens within the sealed cavities forming an exteriorhousing of each stack of internal components, thereby forming theswallowable sensor devices.

Importantly, however, projections included on one or more of the PCboards (such as projections 422 of PC board 220 (FIG. 4)) are notcovered by the exterior housing. This is due to the distal end of eachprojection abutting against the side wall of each mold 810. For example,FIG. 9A illustrates a cross-sectional view of a PC board 920 inserted incavity 812. PC board 920 may be mechanically and electrically coupled toother internal components via central post 930. PC board 920 includes aplurality of projections, such as projection 922, that extend radiallyoutward from a central axis of PC board 920. A distal end 924 ofprojection 922 abuts against a side wall 934 of cavity 812.Consequently, potting material 820 included in cavity 812 is preventedfrom covering distal end 924 of projection 922. As set forth above anddescribed in more detail below with reference to FIGS. 10-12, projection922 may comprise an electrode, a hollow tubing, or a material to beremoved after potting material 820 is hardened.

In another embodiment, indentations are included in side wall 934. Whenthese indentations are aligned with projection 922, distal end 924 isexposed (not encased in potting material) but also leaves an indentationin the hardened potting material (such as indentations 1410, 1420,and/or 1430 illustrated in FIG. 14A). In this embodiment, additionalsensor materials can be deposited with precision depth into theindentation for accurate building of biological/electrical sensors evenafter the base sensor device 104 has been created. Thus, this embodimentaffords a method to customize a sensor device just prior to use, whileallowing substantially short shelf life sensor materials to be utilized.In addition, each indentation may be filled with different amounts of adigestible, protective material to enable timed release of the sensormaterial, as described in more detail below.

In addition to projection 922, a first and second end of central post930 abuts against a base and cap of sealed cavity 812, as illustrated inFIG. 9B. Referring to FIG. 9B, a first end 962 of central post 930 abutsagainst a base 854 of sealed cavity 812. Similarly, a second end 964 ofcentral post 930 abuts against cap 842 of sealed cavity 812. Becausefirst end 962 and second end 964 abut against the base 854 and cap 842,potting material 820 is prevented from covering first end 962 and secondend 964 of central post 930. As a result, when potting material 820hardens to form the exterior housing, first and second ends 962, 964will be exposed to the external environment of the manufacturedswallowable sensor device.

As discussed above with reference to FIG. 2A, first end 962 and secondend 964 provide electrical contacts to the internal components of theswallowable sensor device. These electrical contacts can be used to testthe operability of the swallowable sensor device. For example, a voltagecan be applied between first and second ends 962 and 964 to energize theswallowable sensor device to initiate a self test. Results of the selftest can then be transmitted to an external device. For example, theresults can be transmitted to an external computing device via anacoustic communication signal (such as communication signal 106). Inthis way, the operability of the swallowable sensor device can be testafter it is manufactured and/or before it is ingested by a patient.Furthermore, first and second ends 962 and 964 may be utilized to sensewhen swallowable sensor device 104 has been ingested by human 102.

D. Example Projections

As mentioned above, the projections of one or more PC boards will beexposed to the external environment of the manufactured swallowablesensor device. The projections may comprise an electrode or a hollowtubing. The electrodes may be coupled to a sensor and used to sense acondition of patient 102. The hollow tubing may be configured to delivertreatment, diagnostic aid (dye or radioactive materials), and/or toreceive a sample as it travels through patient 102.

For example, FIG. 10 illustrates a PC board 1020 including a pluralityof projections, such as a first hollow tubing 1032, a second hollowtubing 1036, and an electrode 1034. Each of these projections isdescribed in more detail below.

First hollow tubing 1032 is configured to deliver treatment, such asmedicine, as the swallowable sensor device travels through patient 102.A first end of first hollow tubing 1032 will be exposed to an externalenvironment of a manufactured swallowable sensor device. In anembodiment, a second end of first hollow tubing 1032 is coupled to acontainer 1040. In this embodiment, container 1040 includes a medicine(or some other substance) that is to be delivered to patient 102.Circuitry on PC board 1020 is configured to cause the medicine stored incontainer 1040 to pass through first hollow tubing and into the externalenvironment of the swallowable sensor device.

In an embodiment, the medicine is pressure sealed in container 1040. Inthis embodiment, a relatively low pressure in container 1040 keepsmedicine within container 1040. At a specified time, a micro-pump 1042increases the pressure in container 1040, thereby causing the medicinein container 1040 to pass through first hollow tubing 1032 and into theexternal environment. Micro-pump 1042 is controlled by circuitrycontained on PC board 1020 or other circuitry contained in theswallowable sensor device.

In another embodiment, the medicine in container 1040 is prevented frompassing through first hollow tubing 1032 by a blocking member (such as agate, a membrane, a screen, or some other element). At a specified time,the blocking member is removed, thereby allowing the medicine to passthrough first hollow tubing 1032 into the external environment of theswallowable sensor device. An exemplary material for blocking is amicroencapsulated structure which breaks down at a certain ultrasonicfrequency—such as a frequency that is equal to a frequency generated bya transducer adjacent to tubing 1032 being blocked.

A second hollow tubing 1036 is configured to receive a sample, such as agastrointestinal fluid, as the swallowable sensor device travels throughpatient 102. A first end of second hollow tubing 1036 will be exposed toan external environment of a manufactured swallowable sensor device. Inan embodiment, a second end of second hollow tubing 1036 is coupled tocontainer 1040. In this embodiment, container 1040 is configured toreceive the sample from the gastrointestinal tract of patient 102.Circuitry on PC board 1020 is configured to cause the sample to passthrough second hollow tubing and into container 1040. For example,micro-pump 1042 may decrease the pressure in container 1040, for exampleby pumping out sterile water, thereby forcing the desired sample throughsecond hollow tubing 1036 and into container 1040 through the vacuumcreated in the container 1040.

An embodiment of micro-pump 1042 is further depicted in FIG. 16. Thisembodiment is similar in nature to some ink-jet printers, in that it iscomprised of a chamber or tube that varies it's volume with anelectrical stimulus.

Referring to FIG. 16, assembly 1600 comprises a micro-pump. Simple onedirectional valves 1610 allow flow of fluids from one side of assembly1600 (e.g., the right side) to the other side of assembly 1600 (e.g.,the left side). Furthermore, valve 1610 is detailed as an assembly of abase 1612, with an orifice 1614 that is covered by material 1616, whichis in turn attached to the base by a hinge 1618. The valve assembly 1610is one configuration of many possibilities depending upon the desiredcharacteristics related to in part fluid density, flow capability, andthe frequency of expansion and contraction of the chamber 1650.Alternate embodiments of the valve assembly 1610 do not depart from thespirit and scope of this invention.

Tube 1620 (e.g., the chamber of micro-pump 1042) expands and contractsupon a charge deposited by electrical wiring 1630. A common material fortube 160 (as used, for example, in some ink jet printers) is apiezoelectric material, such as PZT. An example configuration isdepicted in FIG. 16, whereby one of electrical attachments 1630 conductsthrough the wall of tubing 1620 and to the inside conductive surfacethrough a via 1640.

When electrical charges on conductors 1630 are altered, the volume 1650of the inside of the tube 1620 will also alter. A pumping action is aresultant of the expansion and contraction of the volume 1650 incombination with the valves 1610 that allow expansion of fluid to flowfrom the right, and contraction by allowing fluid to flow to the left.The frequency and voltage of the electrical charge alterations willcontrol the rate of the fluid flow, and can be categorized by timing,frequency, current and the like to a certain volume of liquid pumpedthrough the assembly 1600. FIG. 16 depicts merely one of a multitude ofpotential embodiments of micro-pump 1042. One skilled in the art wouldrecognize micro-pump 1042 could be manufactured in many different ways,such as micro-impellers and MEMs structures without departing from thespirit and scope of this invention.

Electrode 1034 is configured to be coupled to a sensor that senses acondition of patient 102. FIG. 11 illustrates an example sensor 1102.Sensor 1102 includes a culture area 1104 that includes a type of culturematerial. The culture material is configured to chemically react tospecific stimuli within the gastrointestinal tract of patient 102. Basedon the chemical reaction, sensor 1102 sends a signal to the internalcircuitry of the swallowable sensor device via electrode 1034. Thesignal may then be sent to an external entity as described above. FIG.12 illustrates an embodiment of swallowable sensor device 104 includinga plurality of sensors 1202 that are exposed to the external environmentof swallowable sensor device 104—i.e., sensors 1202 are not containedwithin housing 108.

E. Example Sensor Implementations

An example application for using swallowable sensor device 104 incombination with biological sensor materials is described below. Aspreviously mentioned, FIG. 8 depicts cavities 812 and electricalcomponents 832. In the below-described example, cavity 812 includesindentations aligning with inserted components 832 such that theindentation abuts distal end 924 of projection 922 (see FIG. 9A). Uponhardening of potting material 820, the indentations of cavities 812leave similar indentations in the hardened potting material 820, and anexposed distal end 924 of projection 922. The indentations may be eitherlocalized with a defined area for each projection 922 (circular, oval,etc), or indentations may run an entire length of the cavity 812, andthey may also define a localized area running between multipleprojections 922 on same or different boards of components 832. Theresulting indentation can be of precise depth and volume.

FIGS. 14A-D depict embodiments of swallowable sensor device 104 having aplurality of indentations. FIG. 14A is an end view depicting swallowablesensor device 104 including, for example, three indentations—at sites1410, 1420, and 1430. As shown, site 1410 and 1420 have multipleprojections 922 into each indentation, while 1430 has only oneprojection. An exemplary implementation for site 1410 compriseselectrical contacts for both projections 922. However, an exemplaryimplementation for site 1430 comprises an electronic sensor package (forexample, an ion sensitive field effect transistor (ISFET) based pHsensor) affixed to the end of projection 922.

In an embodiment, a sensor material 1440 (FIG. 14D) in gel or paste formcan be placed into the sites 1410, 1420, 1430 by simply applying arubber scraping type of tool similar to filling a hole in plaster with aputty knife. A number of methods could be employed to fill one, many, orall sites with the same or different sensor materials 1440. In anembodiment, sensor material 1440 is an enzyme material. Furthermore, aheme oxygenase enzyme material is preferred for detection of bloodwithin the gastrointestinal tract. In another embodiment, an enzymaticmaterial that reacts with a CarcinoEmbryonicAntigen (CEA) effectdetection of cancerous growth in the gastrointestinal tract. Thecapability of sensor device 104 to detect the presence of blood orcancerous growth in combination with the ability to detect the preciselocation of sensor device 104 provides a doctor and patient informationnot available in any other convenient diagnostic. Example methods forprecisely locating sensor device 104 are described in U.S. ProvisionalPatent Application 60/842,360 to Arneson et al., entitled “SwallowableLow Power Sensor Device and System for Communicating with Same” andfiled Sep. 6, 2006, and in U.S. Provisional Patent Application60/924,928 to Arneson et al., entitled “Imaging and Locating Systems andMethods for a Swallowable Sensor Device” and filed Jun. 5, 2007. Theentirety of each of the foregoing applications is incorporated byreference herein. After application of sensor material 1440, theresultant surface of site 1410, 1420, and 1430 is flush with the rest ofsensor device 104.

F. Timed Release Sensor Material

An embodiment of the present invention enables timed release of sensormaterial 1440 based on a thickness of a protective layer, as describedin more detail below.

The enzymatic sensor material 1440 does not function long while exposedto a harsh environment (such as the stomach acid, and in general, thedigestive system itself). Accordingly, a protective layer 1450 can beused to protect sensor material 1440. Importantly, the thickness ofprotective layer 1450 can be manufactured to enable sensor material 1440to be exposed at specific times and/or locations as swallowable sensordevice 104 travels through the digestive system of human 102.

To provide this feature, an embodiment of sensor device 104 includes aplurality of sensors 202, each having sensor material 1440 and a layerof protecting material 1450A, B, C, wherein the layers of protectingmaterial 1450 have differing thickness or density to expose sensormaterial 1440 of each sensor 202 at different times as sensor device 104travels through human 102. Protecting material 1450 may comprise knowntypes of digestible materials, such as known timed release medicinesavailable over-the-counter, as would be apparent to a person skilled inthe relevant art(s). For example, a thickness of material 1450A mayexpose sensor material 1440 to a stomach environment after 30 minutes,while a thickness of material 1450B may expose sensor material 1440 to asmall intestine environment after 1 hour. Given a sensor materialfunctional life span of 30 minutes, and a desired operational time forsensor device 104 of approximately 24 hours, for example, thenembodiments of the present invention include 48 (or more) differentthicknesses for protective layer 1450.

An embodiment of this present invention creates sensor device 104 from acavity 812 that has a tapered portion of the length of the cavity, asillustrated for example in FIG. 14B. The resultant shape of the hardenedpotting materials produces a tapered assembly. The tapered assembly isapplied to a consistent diameter mold or apparatus that applies adigestible material to the assembly. The result is a tapered thickness1450 of digestible material covering sensor material 1440. In thismethod, sensor materials 1440 of swallowable sensor device 104 are timereleased to the environment, and at a rate whereby at least one ofsensors 202 is active at any point in time throughout a desired periodof time (such as approximately 24 hours, which is an average time forswallowable sensor device 104 to pass through human 102).

In an alternate embodiment, sensor material 1440 can be applied at auniform thickness, such as with a uniform spray technique, into a site1410, 1420, and 1430 of different thickness and volume, as illustratedfor example in FIG. 14C. In another part of a process, digestiblematerial 1450 can be applied so as to fill the remainder of the volumeof sites 1410, 1420, and 1430. The result is similar to the taperedexample, in that a sensor material 1440 is covered by digestiblematerials 1450 of varying thicknesses.

FIGS. 15A-D depict several embodiments of timed release biologicalsensor materials 1440. FIG. 15A depicts an example timed releaseembodiment. A sensor comprises an electrically conductive material 1561,upon which an antibody 1562 is affixed. In general, a digestiblematerial 1565 covers antibody 1562 with different depths for exposure toa potential antigen 1563 in a timed release fashion. FIG. 15B depicts arandomly distributed mixture of antibodies within a digestible material,for example a polymer matrix. FIG. 15C depicts an example of differentdepth indentations of 1410, 1420, and 1430 depicted to FIG. 14. FIG. 15Ddepicts a further embodiment illustrating a fixed depth indentation witha tapered depth digestible material 1565.

F. Example Testing Methods

Ingestible, pill-formed and packaged electronic products are a newconcept. Although packaging and production of electronics is well-knownand packaging and production of medicine is well-known, a process thatcombines both provides some interesting issues. Final testing ofproduction pieces of electronics and resultant packaging can be done ina delicate environment, preserved with electrostatic bags and otherprotective packaging. Medicines also have a delicate environment forbiological sensitivity, but not for electrical sensitivity. Thus, aprocess for a combination of packaging and testing of ingestibleelectronic devices is a new requirement, and an object of this presentinvention.

FIGS. 17A and 17B respectively depict a top view and a side view of anassembly 1700. Assembly 1700 comprises an industry typical package 1710(such as a heat formable plastic) and electrical pathways 1720. Thepackage material 1710 is modified from a typical approach withelectrical pathways 1720. Specifically, electrical pathways 1720 startfrom an edge accessible connection point 1740, and terminate internallyat connection points 1730. Importantly, electrical pathways 1720 remainin a flat state as depicted in FIGS. 17A and 17B. Depending upon cost,speed, complexity, and a type of electrical signal carried, electricalpathways 1720 may comprise copper, aluminum, a silver paste, or someother conductive material as would be apparent to a person skilled inthe relevant art(s). Additionally, the conductive material may beapplied to package material 1710 in a process such as printing, asubtractive or additive process such as is typical in circuit boardmanufacturing, and also a foil cut and adhesive process also typicallyfound in a printing/packaging industry. A person skilled in the artwould understand how to select a material and method of conductivepathways 1720 that would deliver both electrical performance necessary,while achieving desired volume and cost goals. Selection of additionalmaterials and methods for affixing these materials to package 1710 doesnot depart from the spirit and scope of this invention. In anotherembodiment, edge accessible connection points 1740 may be located onboth sides of assembly 1700 as would be apparent to a person skilled inthe art.

Assembly 1700 is then introduced into a mold, with heat and some form ofpressure common with the molding of plastic packaging. The mold causeswells 1765 to be formed in assembly 1700, as depicted in FIGS. 17C and17D. Wells 1765 are created of the shape and size to deposit aningestible electronic device such as device 104 of FIG. 1. In themolding process, connection points 1730 change shape to become threedimensional pathways 1780 extending into well 1765, while retainingtheir electrical conductivity. Optionally, an edge connection point 1740may transform into a heightened external connection point 1790 in thefinal form. Assembly 1700 now provides a convenient electricalconnection point 1790, carrying electrical signals through pathways to apoint 1780 on the package that now electrically connects to programmingand/or test points on ingestible device 104 that can be deposited intowell 1765.

FIGS. 18A and 18B respectively illustrate a top view and a side view ofa machine that deposits ingestible electronic devices 1890 (such asdevice 104 of FIG. 1) into wells 1765 of assembly 1700. As assembly 1700moves in a conveyor-belt fashion, a mechanism 1820 directs one device1890 at a time from feeder 1810 and applies a slight pressure on device1890 to urge it into one of wells 1765. When urged into a well 1765,test points 1895 on device 1890 are then electrically connected toconnection points 1830 of assembly 1700. As shown in FIG. 18, finalassembly 1850 results in electrical connection points 1830 that areconductive to electronic devices in the assembly. In a final packaging,assembly 1850 may be covered by a film or label in order to contain thedevices 1890 and/or provide biological containment or isolation from anon-sterile distribution environment. The film or label is applied suchthat electrical connection points 1830 are not electrically insulated,for example with a shorter width label than the width of assembly 1850.Furthermore, upon testing completion, electrical connection points 1830may be removed, or trimmed at a factory, by simply cutting this edgefrom the final packaging.

Assembly 1850 illustrates the capability to both biologically contain aningestible electronic device while facilitating direct electricalconnection for a variety of testing, programming, and energy transfer(for example, battery charging) functions while not requiring all of thetest platforms and environments within and between to be sterilizedand/or germ free. Furthermore, as depicted in FIG. 18, final assembly1850 allows individual testing of devices 1890, either sequentially orin parallel. A person skilled in the relevant art(s) would understandhow to develop a test platform external, but applied, to assembly 1850that tests, programs, charges, and verifies each of a multitude ofdevices 1890 within the assembly serially, in parallel, or anycombination thereof. Such test devices are hereby conceived and do notdepart from the spirit and scope of the present invention.

In an alternate embodiment, test points 1895 can be electronicallyconnected through conductive pathways 1720 and 1730, with optionaladditional electronic components and/or power supplies deposited uponpackage material 1710. In this embodiment, the removal of electronicdevice 1890 from assembly 1850 is detectable or determinable. Uponremoval, electronic device 1890 can be configured to autonomouslyprepare for subsequent ingestion within an animal or human, for exampleby turning one or more features and functions.

G. Layered Structure

In an embodiment, swallowable sensor device 104 has a layered structureto provide efficient transfer of sound energy into the surroundingmedium (e.g., liquid, solid, human tissue or viscoelastic materials).Each layer or composite layers has a particular acoustic impedance. Thematerial closest to the sensor has an acoustic impedance that is a largepercentage of the sensor. As the material or material layers transitionto the outside of swallowable sensor device 104, the fractionalpercentage of the material's acoustic impedance drops to match thesurrounding medium. The change in material properties can beaccomplished by multiple layers of materials (FIG. 19) or by a singleanisotropic material having a distributed impedance or density (FIG.20).

FIG. 19 illustrates an embodiment in which the change in materialproperties of swallowable sensor device 104 is accomplished by multiplelayers of materials. As illustrated in FIG. 19, swallowable sensordevice 104 includes an acoustic sensor 1901, an intermediate layer 1903,and an outer layer 1905. Acoustic sensor 1901 comprises a transducerthat converts mechanical energy into electrical energy, and vice versa.Intermediate layer 1903 is configured to have an impedance similar tothe acoustic impedance of acoustic sensor 1901. And, outer layer 1905 isconfigured to have an impedance similar to the acoustic impedance of theexternal environment. Intermediate layer 1903 and outer layer 1905 maybe layered with additional materials to their characteristics. Forexample, intermediate layer 1903 can be configured to be harder thanouter layer 1905. Although swallowable sensor device 104 as illustratedin FIG. 19 includes only intermediate layer 1903 and outer layer 1905,it is to be appreciated that additional layers may be included onswallowable sensor device 104. The layers of swallowable sensor device104, illustrated in FIG. 19, may be applied using mechanical,electrical, magnetic, and/or chemical fastening. For example, thevarious layers of material may be disposed on swallowable sensor device104 through an injection molding process. As another example, thevarious layers may be disposed on swallowable sensor device 104 througha dip coating process, wherein swallowable sensor device 104 issuccessively dipped in one or more vats of materials (such as latex) toachieve the appropriate acoustic layering.

FIG. 20 illustrates an embodiment in which the change in materialproperties of swallowable sensor device 104 is accomplished by a singleanisotropic material (distributed impedance or density) according to anembodiment of the present invention. As illustrated in FIG. 20,swallowable sensor device 104 includes an acoustic sensor 2001 and ananisotropic layer 2003. Acoustic sensor 2001 is a transducer thatconverts mechanical energy to electrical energy, and vice versa.Anisotropic layer 2003 has an acoustic impedance that various withdistance—such that the inner portions of anisotropic layer 2003 have anacoustic impedance similar to acoustic sensor 2001, whereas the outerportions of anisotropic layer 2003 have an acoustic impedance similar tothe external environment.

In an embodiment, the anisotropic layer 2003, illustrated in FIG. 20, ismanufactured using a UV epoxy (such as potting material 820) in anoxygen-rich environment. The oxygen inhibits the UV cure. Consequently,if the layer 2003 is UV cured in an oxygen-rich environment, the outerportions of layer 2003 will not be cured as much as the inner layers.The amount of oxygen in the environment can be controlled to cause theacoustic impedance of the exterior of anisotropic layer 2003 tosubstantially match the acoustic impedance of human or animal tissue,while the inner portions of layer 2003 will be UV cured to substantiallymatch the acoustic impedance of acoustic sensor 2001.

V. Example Computer System Embodiments

According to an example embodiment, a swallowable sensor device mayexecute computer-readable instructions to perform its functions.Furthermore, a sensor link module for communicating with the swallowablesensor device may execute computer-readable instructions to communicatewith the swallowable sensor device. Still further, a computing devicemay execute computer-readable instructions to control and communicatewith the swallowable sensor device and/or the sensor link module, and/orto process data obtained by the swallowable sensor device and/or sensorlink module, as described above. Still further, a test kit and medicaldiagnostic network system may each execute computer-readableinstructions to perform its functions.

In one embodiment, one or more computer systems are capable of carryingout the functionality described herein. An example of a computer system1300 is shown in FIG. 13.

The computer system 1300 includes one or more processors, such asprocessor 1304. The processor 1304 is connected to a communicationinfrastructure 1306 (e.g., a communications bus, cross-over bar, ornetwork). Various software embodiments are described in terms of thisexemplary computer system. After reading this description, it willbecome apparent to a person skilled in the relevant art(s) how toimplement the invention using other computer systems and/orarchitectures.

Computer system 1300 can include a display interface 1302 that forwardsgraphics, text, and other data from the communication infrastructure1306 (or from a frame buffer not shown) for display on the display unit1330.

Computer system 1300 also includes a main memory 1308, preferably randomaccess memory (RAM), and may also include a secondary memory 1310. Thesecondary memory 1310 may include, for example, a hard disk drive 1312and/or a removable storage drive 1314, representing a floppy disk drive,a magnetic tape drive, an optical disk drive, etc. The removable storagedrive 1314 reads from and/or writes to a removable storage unit 1318 ina well known manner. Removable storage unit 1318 represents a floppydisk, magnetic tape, optical disk, etc. which is read by and written toby removable storage drive 1314. As will be appreciated, the removablestorage unit 1318 includes a computer usable storage medium havingstored therein computer software and/or data.

In alternative embodiments, secondary memory 1310 may include othersimilar devices for allowing computer programs or other instructions tobe loaded into computer system 1300. Such devices may include, forexample, a removable storage unit 1322 and an interface 1320. Examplesof such may include a program cartridge and cartridge interface (such asthat found in video game devices), a removable memory chip (such as anerasable programmable read only memory (EPROM), or programmable readonly memory (PROM)) and associated socket, and other removable storageunits 1322 and interfaces 1320, which allow software and data to betransferred from the removable storage unit 1322 to computer system1300.

Computer system 1300 may also include a communications interface 1324.Communications interface 1324 allows software and data to be transferredbetween computer system 1300 and external devices. Examples ofcommunications interface 1324 may include a modem, a network interface(such as an Ethernet card), a communications port, a Personal ComputerMemory Card International Association (PCMCIA) slot and card, etc.Software and data transferred via communications interface 1324 are inthe form of signals 1328 which may be electronic, electromagnetic,optical or other signals capable of being received by communicationsinterface 1324. These signals 1328 are provided to communicationsinterface 1324 via a communications path (e.g., channel) 1326. Thischannel 1326 carries signals 1328 and may be implemented using wire orcable, fiber optics, a telephone line, a cellular link, a radiofrequency (RF) link and other communications channels.

In this document, the terms “computer program medium” and “computerusable medium” are used to generally refer to media such as removablestorage drive 1314 and a hard disk installed in hard disk drive 1312.These computer program products provide software to computer system1300. The invention is directed to such computer program products.

Computer programs (also referred to as computer control logic) arestored in main memory 1308 and/or secondary memory 1310. Computerprograms may also be received via communications interface 1324. Suchcomputer programs, when executed, enable the computer system 1300 toperform the features of the present invention, as discussed herein. Inparticular, the computer programs, when executed, enable the processor1304 to perform the features of the present invention. Accordingly, suchcomputer programs represent controllers of the computer system 1300.

In an embodiment where the invention is implemented using software, thesoftware may be stored in a computer program product and loaded intocomputer system 1300 using removable storage drive 1314, hard drive 1312or communications interface 1324. The control logic (software), whenexecuted by the processor 1304, causes the processor 1304 to perform thefunctions of the invention as described herein.

In another embodiment, the invention is implemented primarily inhardware using, for example, hardware components such as applicationspecific integrated circuits (ASICs). Implementation of the hardwarestate machine so as to perform the functions described herein will beapparent to persons skilled in the relevant art(s).

In yet another embodiment, the invention is implemented using acombination of both hardware and software.

VI. Conclusion

Methods and systems for manufacturing a swallowable sensor device havebeen presented. Example embodiments described above relate to a humansubject. This is for illustrative purposes, and not limitation.Embodiments of the present invention are applicable to other types ofanimals, including livestock (cattle, sheep, pigs, chickens, turkeys,ostriches, etc.), pets (e.g., dogs, cats, horses, etc.), and otheranimals of interest such as race horses or other performance/sportanimals. Such applicability to these types of animals, and other types,will be apparent to persons skilled in the relevant art(s) from theteachings herein, and is within the scope and spirit of embodiments ofthe present invention.

Furthermore, example embodiments described above relate to passing aswallowable sensor device through a gastrointestinal tract, forillustrative purposes. However, embodiments of the present invention areapplicable to farther bodily systems other than the gastrointestinaltract, including the circulatory system, the urinary tract, and otherbodily systems and additionally other means of entry or implant into abody cavity of an animal or human. Such applicability to other types ofbodily systems will be apparent to persons skilled in the relevantart(s) from the teachings herein, and is within the scope and spirit ofembodiments of the present invention.

In addition, it should be understood that spatial descriptions (e.g.,“above,” “below,” “up,” “left,” “right,” “down,” “top,” “bottom,”“vertical,” “horizontal,” etc.) used herein are for purposes ofillustration only, and that practical implementations of the structuresdescribed herein can be spatially arranged in any orientation or manner.

Moreover, it is to be appreciated that the Detailed Description section,and not the Abstract section, is intended to be used to interpret theclaims. The Abstract section may set forth one or more but not allexemplary embodiments of the present invention as contemplated by theinventor(s), and thus, is not intended to limit the present inventionand the appended claims in any way.

1. A method for manufacturing a swallowable sensor device, comprising:mechanically coupling a plurality of internal components of theswallowable sensor device, wherein the plurality of internal componentsincludes a printed circuit (PC) board having a plurality of projectionsextending radially outward; filling a cavity with a potting material;inserting the mechanically coupled components into the cavity, a distalend of each projection abutting against a side wall of the cavitythereby preventing the potting material from covering the distal end ofeach projection; and sealing the cavity with a cap, wherein the pottingmaterial hardens within the sealed cavity to form a housing of theswallowable sensor device such that the distal end of each projection isexposed to an external environment of the swallowable sensor device. 2.The method of claim 1, wherein the cavity is filled with the pottingmaterial before inserting the mechanically coupled components therein.3. The method of claim 1, wherein the cavity is filled with the pottingmaterial after inserting the mechanically coupled components therein. 4.The method of claim 1, wherein the plurality of internal components aremechanically coupled using a post.
 5. The method of claim 4, wherein afirst end of the post abuts against a base of the cavity and a secondend of the post abuts against the cap thereby preventing the pottingmaterial from covering the first and second ends of the post.
 6. Themethod of claim 5, further comprising: providing a voltage between thefirst and second ends of the post to test operability of the swallowablesensor device.
 7. The method of claim 4, wherein the post provides anelectrical coupling between the plurality of PC boards.
 8. The method ofclaim 4, wherein the post comprises a transducer configured to convertelectrical energy to mechanical energy.
 9. The method of claim 4,wherein the plurality of internal components are annularly-shaped andmechanically coupled by the post along a common central axis.
 10. Themethod of claim 1, wherein at least one of the projections comprises anelectrode, and the method further comprises electrically coupling asensor to the electrode.
 11. The method of claim 1, wherein at least oneof the projections comprises a hollow tubing coupled to a containerincluded inside the housing of the swallowable sensor device.
 12. Themethod of claim 1, wherein the plurality of internal components includesa battery.
 13. The method of claim 1, wherein the plurality of internalcomponents includes a transducer that is configured to convertelectrical energy to mechanical energy.
 14. A system for manufacturing aswallowable sensor device, comprising: means for mechanically coupling aplurality of internal components of the swallowable sensor device,wherein the plurality of internal components includes a printed circuit(PC) board having a plurality of projections extending radially outward;means for filling a cavity with a potting material; means for insertingthe mechanically coupled components into the cavity, a distal end ofeach projection abutting against a side wall of the cavity therebypreventing the potting material from covering the distal end of eachprojection; and means for sealing the cavity with a cap, wherein thepotting material hardens within the sealed cavity to form a housing ofthe swallowable sensor device such that the distal end of eachprojection is exposed to an external environment of the swallowablesensor device.
 15. The system of claim 14, wherein the means for fillingthe cavity comprises means for filling the cavity with the pottingmaterial before inserting the mechanically coupled components therein.16. The system of claim 14, wherein the means for filling the cavitycomprises means for filling the cavity with the potting material afterinserting the mechanically coupled components therein.
 17. The system ofclaim 14, wherein the means for mechanically coupling the plurality ofinternal components comprises a post.
 18. The system of claim 17,wherein a first end of the post abuts against a base of the cavity and asecond end of the post abuts against the cap thereby preventing thepotting material from covering the first and second ends of the post.19. The system of claim 18, further comprising: means for providing avoltage between the first and second ends of the post to testoperability of the swallowable sensor device.
 20. The system of claim17, wherein the post provides an electrical coupling between theplurality of internal components.
 21. The system of claim 17, whereinthe post comprises a transducer configured to convert electrical energyto mechanical energy.
 22. The system of claim 17, wherein the pluralityof internal components are annularly-shaped and mechanically coupled bythe post along a common central axis.
 23. The system of claim 14,wherein at least one of the projections comprises an electrode, and thesystem further comprises means for electrically coupling a sensor to theelectrode.
 24. The system of claim 14, wherein at least one of theprojections comprises a hollow tubing coupled to a container, whereinthe container is included inside the housing of the swallowable sensordevice.
 25. The system of claim 14, wherein the plurality of internalcomponents includes a transducer that is configured to convertelectrical energy to mechanical energy.
 26. A swallowable sensor deviceconfigured to be ingested by an animal, comprising: one or more sensorseach configured to sense a received stimulus; and a communicationmodule, coupled to the one or more sensors, that transmits acommunication signal, the communication signal including informationregarding stimuli sensed by the one or more sensors; wherein the one ormore sensors are covered by digestible material, enabling the one ormore sensors to be released after the animal digests the digestiblematerial.
 27. The swallowable sensor device of claim 26, wherein the oneor more sensors are covered by respective thicknesses of the digestiblematerial, enabling the one or more sensors to be released at respectivetimes after the animal digests the respective thicknesses of thedigestible material.
 28. The swallowable sensor device of claim 26,wherein the one or more sensors comprise a heme oxygenase enzymematerial.
 29. The swallowable sensor device of claim 26, wherein the oneor more sensors comprise a material that reacts with aCarcinoEmbryonicAntigen (CEA).
 30. A swallowable sensor deviceconfigured to be ingested by an animal, comprising: a communicationmodule comprising an acoustic sensor that converts electrical energy tomechanical energy; and a layered structure that covers the communicationmodule, the layered structure having an acoustic impedance that varieswith distance from an interior portion to an exterior portion of thelayered structure.
 31. The swallowable sensor device of claim 30,wherein the layer structure comprises: an intermediate layer having anacoustic impedance substantially similar to an acoustic impedance of theacoustic sensor; and an outer layer having an acoustic impedancesubstantially similar to an acoustic impedance of an environment withinthe animal.
 32. The swallowable sensor device of claim 30, wherein thelayer structure comprises: an anisotropic layer having an acousticimpedance that decreases with distance from an interior portion to anexterior portion, such that the interior portion of the anisotropiclayer has an acoustic impedance substantially similar to an acousticimpedance of the acoustic sensor and the exterior portion of theanisotropic layer has an acoustic impedance substantially similar to anacoustic impedance of an environment within the animal.
 33. Theswallowable sensor device of claim 32, wherein the anisotropic layercomprises a UV-curable epoxy.
 34. A method for mechanically andelectrically coupling internal components of a swallowable sensordevice, comprising: preparing a plurality of printed circuit (PC) boardshaving opposing first and second surfaces, wherein each PC board has oneor more spacers disposed on the first surface, a plurality of holesextending between the first and second surfaces, and a keyed holeextending between the first and second surfaces; contiguously placingeach PC board on a conductor that is aligned with the keyed hole of eachPC board, such that the one or more spacers of a first PC board abutagainst the second surface of a second PC board; and inserting aplurality of conductors through the plurality of holes in each PC board.35. A method for mechanically and electrically coupling internalcomponents of a swallowable sensor device, comprising: preparing aplurality of printed circuit (PC) boards having opposing first andsecond surfaces, wherein each PC board has a plurality of keyed holesextending between the first and second surfaces; placing each PC boardon conductors aligned with the keyed holes of each PC board to form a PCassembly; compressing the PC assembly with a pre-determined pressure;and fixedly connected a first and last PC board of the PC assembly tothe conductors.
 36. A method for testing swallowable sensor devices,comprising: providing an assembly having a plurality of wells formedtherein, each well having connection points that are electricallycoupled to edge connection points; urging the respective swallowablesensor devices into the respective wells formed in the assembly, whereintests points on the respective swallowable sensor devices areelectrically connected to the electrical connection points of therespective wells; and sending electrical signals through the edgeconnection points to test the swallowable sensor devices.
 37. The methodof claim 36, further comprising: sealing the swallowable sensor deviceswithin the assembly.